edfa817773
switch to using C99-style comments everywhere in preprocessed assembler. The reason is that lines starting with the regexp '^[[:space:]]#' are treated as preprocessing directives, and while it seems to work now with GCC, it's not necessarily has to work. Use C99 comments `//' for the trailing comments to save whitespace.
81 lines
2.2 KiB
ArmAsm
81 lines
2.2 KiB
ArmAsm
/*
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* Copyright (c) 1998 Robert Nordier
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms are freely
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* permitted provided that the above copyright notice and this
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* paragraph and the following disclaimer are duplicated in all
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* such forms.
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*
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* This software is provided "AS IS" and without any express or
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* implied warranties, including, without limitation, the implied
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* warranties of merchantability and fitness for a particular
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* purpose.
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*
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* $FreeBSD$
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*/
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.set SIO_PRT,SIOPRT // Base port
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.set SIO_FMT,SIOFMT // 8N1
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.set SIO_DIV,(115200/SIOSPD) // 115200 / SPD
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.globl sio_init
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.globl sio_flush
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.globl sio_putc
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.globl sio_getc
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.globl sio_ischar
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/* void sio_init(void) */
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sio_init: movw $SIO_PRT+0x3,%dx // Data format reg
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movb $SIO_FMT|0x80,%al // Set format
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outb %al,(%dx) // and DLAB
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pushl %edx // Save
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subb $0x3,%dl // Divisor latch reg
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movw $SIO_DIV,%ax // Set
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outw %ax,(%dx) // BPS
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popl %edx // Restore
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movb $SIO_FMT,%al // Clear
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outb %al,(%dx) // DLAB
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incl %edx // Modem control reg
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movb $0x3,%al // Set RTS,
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outb %al,(%dx) // DTR
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incl %edx // Line status reg
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/* void sio_flush(void) */
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sio_flush.0: call sio_getc.1 // Get character
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sio_flush: call sio_ischar // Check for character
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jnz sio_flush.0 // Till none
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ret // To caller
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/* void sio_putc(int c) */
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sio_putc: movw $SIO_PRT+0x5,%dx // Line status reg
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xor %ecx,%ecx // Timeout
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movb $0x40,%ch // counter
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sio_putc.1: inb (%dx),%al // Transmitter
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testb $0x20,%al // buffer empty?
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loopz sio_putc.1 // No
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jz sio_putc.2 // If timeout
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movb 0x4(%esp,1),%al // Get character
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subb $0x5,%dl // Transmitter hold reg
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outb %al,(%dx) // Write character
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sio_putc.2: ret $0x4 // To caller
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/* int sio_getc(void) */
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sio_getc: call sio_ischar // Character available?
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jz sio_getc // No
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sio_getc.1: subb $0x5,%dl // Receiver buffer reg
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inb (%dx),%al // Read character
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ret // To caller
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/* int sio_ischar(void) */
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sio_ischar: movw $SIO_PRT+0x5,%dx // Line status register
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xorl %eax,%eax // Zero
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inb (%dx),%al // Received data
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andb $0x1,%al // ready?
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ret // To caller
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